"I was just on my way home after a trip to France. I was visiting my children in Plumstead and I had taken a 53 bus to get to Parliament Square where I was going to meet my children and walk to Victoria coach station before getting the coach to Helston in Cornwall.

"I was sitting on the lower deck and the bus stopped. I could clearly see a body in the road and a crashed car. I trained as a first aider when I was a Brownie leader, so I asked someone to watch my bag and then got off to see if I could help.

"I went over to the body where there was a lady sitting there and she said he was dead. She had comforted him by putting something under his back and a jacket over his head. I took his pulse and there was none. I couldn't see the man's face but I could see no evidence that suggested someone had tried to cut off his head. I could see nothing on him to suggest that he was a soldier.

"Then a black guy with a black hat and a revolver in one hand and a cleaver in the other came over. He was very excited and he told me not to get close to the body. I didn't really feel anything. I was not scared because he was not drunk, he was not on drugs. He was normal. I could speak to him and he wanted to speak and that's what we did.

"I spoke to him for more than five minutes. I asked him why he had done what he had done. He said he had killed the man because he [the victim] was a British soldier who killed Muslim women and children in Iraq and Afghanistan. He was furious about the British army being over there.

"There was blood on the pavement by the car where the man on the ground had been hit by it. At first there was no blood by the body but as I talked to the man it began to flow which worried me because blood needs a beating heart to flow. But I didn't want to annoy the man by going back to the body.

"I asked him what he was going to do next because the police were going to arrive soon. He said it was a war and if the police were coming, he was going to kill them. I asked him if that was a reasonable thing to do but it was clear that he really wanted to do that. He talked about war but he did not talk about dying and then he left to speak to someone else.

"I went to speak to the other man who was quieter and more shy. I asked him if he wanted to give me what he was holding in his hand, which was a knife but I didn't want to say that. He didn't agree and I asked him: 'Do you want to carry on?' He said: 'No, no, no.' I didn't want to upset him and then the other man came back to me. I asked him what he wanted to do next.

"At that point, there were so many people around that I didn't want him to get scared or agitated. I kept talking to him to keep him occupied.

"Then I saw my bus was moving and I knew that the police would arrive very soon. I asked him if there was anything else I could do for him because my bus was about to leave and he said no.

"I got on the bus and, after 10 seconds, someone came on and told everyone to get down. I saw a police car pulling up and a police man and policewoman getting out. The two black men ran towards the car and the officers shot them in the legs, I think.

"When the shooting started, I was not scared. There weres so many women screaming and crying on the bus, it took me a minute to calm them down. I didn't have a moment to think of myself.

"I could see the man with the black hat on was badly hurt as he was being operated on but both were still moving.

"The bus then started to move away. They dropped us in the middle of Lewisham which really annoyed me because I had no idea how to get from there to Parliament Square. "I am just happy that I managed to do something that might have prevented more trouble. I feel fine at the moment but I suppose the shock could hit me later."